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bpf, arm64: Support 32-bit offset jmp instruction

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Add support for 32-bit offset jmp instructions. Given the arm64 direct jump
range is +-128MB, which is large enough for BPF prog, jumps beyond this range
are not supported.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Florent Revest <revest@chromium.org>
Acked-by: Florent Revest <revest@chromium.org>
Link: https://lore.kernel.org/bpf/20230815154158.717901-6-xukuohai@huaweicloud.com
This commit is contained in:
Xu Kuohai 2023-08-15 11:41:56 -04:00 committed by Daniel Borkmann
parent 1104247f3f
commit c32b6ee514
1 changed files with 5 additions and 1 deletions
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6
arch/arm64/net/bpf_jit_comp.c
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@ -982,7 +982,11 @@ emit_bswap_uxt:
/* JUMP off */
case BPF_JMP | BPF_JA:
jmp_offset = bpf2a64_offset(i, off, ctx);
case BPF_JMP32 | BPF_JA:
if (BPF_CLASS(code) == BPF_JMP)
jmp_offset = bpf2a64_offset(i, off, ctx);
else
jmp_offset = bpf2a64_offset(i, imm, ctx);
check_imm26(jmp_offset);
emit(A64_B(jmp_offset), ctx);
break;